Three integrated research projects are proposed for the purpose of continuing cross sectional and longitudinal studies of children with and without language impairment. During the last funding period, participants were identified in kindergarten, and followed through the fourth grade. This particular sample of 570 children is unique because it was obtained using population sampling methods in a prior epidemiological study of specific language impairment (SLI). The three complementary projects focus on the causes, course, and outcomes of language impairment from elementary through high school years. Collectively these issues center on when we should consider a child to have language impairment and why. As an integrated program, this research addresses questions fundamental to the field concerning the diagnosis of language impairment in children. One project will address questions concerning the course of language impairment in children. Participants will reach 11th grade by the end of the proposed study period, having been followed since kindergarten. We will be able to determine long-term language outcomes, and patterns of language growth, using the same participants, from ages 5 through 16. We intent also to identify predictors of individual differences in these language growth patterns. A second project will examine the relationship between information processing, speed and capacity, and language status. A key question in this project probes the extent to which individual differences in language performance are associated with general cognitive mechanisms, or those mechanisms specific to language. The third pro project examines the relationship between information processing, speed and capacity, and language status. It attends especially to the role of processing capacity on reading and listening comprehension. Accomplishments of the integrated program will benefit from the context of past findings; established infrastructure; trained research personnel; and its established relationships with child subjects, parents, school systems, and other key parties.